Alarm system for electric refrigerators



Aug. 24, 1948. BAUMAN 2,447,893

ALAR SYSTEM FOR ELECTRIC REFRIGERATORS Filed Aug. 30, 1944 3 Sheets-Sheet l 948. J. J. BAUMAN ALARII SYSTBI FOR ELECTRIC REFRIGERATORS 3 Sheets-Sheet 2 Filed Aug. 30, 1944 Aug. 8- J. J. BAUMAN 2,447,893

ALARII SYSTEI FOR ELECTRIC REFRIGERATORS Filed Aug. 30, 1944 3 Sheets-Sheet 3 Patented Aug. 24, 1948 ALARM SYSTEM FOR ELECTRIC REFRIGERATORS John J. Bauman, Abington, Pa., assignor, by mesne assignments, to Philco Corporation, Philadelphia, Pa., a corporation of Pennsyl- Vania Application August 30, 1944, Serial No. 551,977

' 29 Claims. (Cl. 62-2) This invention relates to refrigerators and more particularly to novel means for indicating an abnormal or undesired condition of the refrigerating apparatus. The invention is especially applicable to that type of refrigerator having a freezer chest compartment for the storage of frozen food.

In the case of an ordinary household refrigerator which is used to store foodstuffs for daily use, any failure or abnormal condition would be readily noticed and therefore the provision of an alarm or indicator is not usually warranted. However, in the case of a refrigerator having provision for storing foodstuffs for use at some future time, the provision of such an indicator is highly desirable. An example of such a refrigerator is one having a freezer chest compartment in which a large quantity of foodstuffs may be stored. In such case, an abnormal condition is likely to go unnoticed and the resulting spoilage of foodstuffs may be very substantial. The desirability of a suitable alarm or indicator in such an apparatus is quite apparent.

The principal object of the present invention is to provide a novel apparatus-for the purpose above indicated, which is adapted to give an indication of an abnormal condition that would,

if undetected, cause excessively high or low temperatures in a refrigerated compartment.

Another object of the invention is to provide means for preventing the indicator from operating in response to adjustments from one temperature condition to another, or during the lowering or so-called "pulldown" of the temperature from ambient temperature.

A further object of the invention is to provide a novel indicating arrangement in cooperative association with an adjustable thermostatic control device, which arrangement is adapted to give an indication of any abnormal condition, but which is automatically rendered inoperative when the thermostatic control device is adjusted in a manner that would otherwise cause undesired or unnecessary operation of the indicator.

Another object of the invention is to provide an indicating arrangement which serves not only as an alarm device but also as a signaling device to indicate that a desired temperature has been reached.

Still another object of the invention is to provide a novel indicator which is adapted to operate intermittently rather than continuously, thus prolonging the life of the indicator and conserving the electrical energy which operates the same.

The invention may be fully understood by reference to the accompamring drawings, in which:

Fig. 1 illustrates a refrigerating apparatus embodying the invention;

Fig. 2 is a plan view of the control device with the latter in oif" position as in Fig. 1.

iii

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1 showing the adjustable cams in the position corresponding to the off position of Fig. 2;

Fig. 4 is a face view of an improved indicator device which may be used if desired;

Fig. 5 is a side elevational view of the same device;

Fig. 6 illustrates a modification of the apparatus of Fig. 1; and

Fig. 7 shows another embodiment of the invention.

Referring particularly to Fig. 1, there is shown on a greatly reduced scale an electric refrigerator including a freezer chest compartment l0 having an associated cooling unit or evaporator l l. The refrigerating system includes the usual motorcompressor l2 and condenser l3. The present invention is not concerned with the details of the refrigerator cabinet structure or the refrigerating system, which may be of conventional form.

In accordance with the present invention, there is provided a controlling and indicating apparatus designated generally by reference character ll. The parts of this apparatus are shown as being conveniently mounted on a support or casing it which may be suitably disposed as a part of the entire refrigerating apparatus. The operation of the refrigerating system is controlled by a thermostatic control device which preferably includes a feeler bulb i6 arranged to detect temperature variations within the compartment Ill. As illustrated, the feeler bulb may be positioned in engagement with a portion of the refrigerant conduit whose temperature determines the temperature within compartment ill. The feeler bulb operates a bellows ll through the medium of an expansible fluid within the conduit I8, as will be well understood. The bellows l1 actuates a bell crank lever l9, which is pivoted at 20, against the action of a. spring 2i whose compression is adjustable by the manual rotation of control knob 22. Specifically, the lower end of spring 2i engages lever is while the upper end of the spring abuts against a member 23 threadedly engaging a shaft 24 which is mounted for rotative movement only. Rotation of shaft 24 through knob 22 varies the axial position of member 23, th varying the pressure of the spring 2|.

A switch 25 is operated by lever l9 and serves to control the motor circuit 26 which is connected to the supply line 21. Switch 25 comprises a stationary contact member 28, suitably insulated from casing l5, and a movable contact member 29 carried by arm 30, which is pivoted on a knifeedge pivot 3| on the stationary bracket 32. A spring 33 has one end connected to arm 30 at 34 while the other end of the spring is connected to lever I! at 3!. Normally the parts are disposed as shown, and the switch 25 is open. However, when the lever l9 moves clockwise about its pivot 28, the spring 33 is moved to the right of the pivot 3| and causes arm 39 to move so as to bring the contact 29 into engagement with contact 28. Thus, whenever the temperature within compartment l8 rises sufliciently to cause operation of the above described parts, the refrigerating system is operated to lower the said temperature. It will be apparent that the adjustment of the pressure of spring 2| by means of knob 22 determines the temperature which will be maintained within compartment I0.

As shown in Fig. 2, the control knob 22 has four principal positions which are preferably designated. respectively, off, "normal," "cold" and continuous. The "normal" setting is used for ordinary refrigerator operation in the manner of the usual domestic refrigerator. This position might, for example, correspond to a temperature condition in the neighborhood of from '38 to 40 F. The cold setting is used to maintain stored foodstuffs at a lower temperature (for example, to F.) for future use. The "continuous" setting is used to quick-freeze foodstuffs by rapidly decreasing the temperature within compartment NJ to a substantially lower temperature than that which obtains during the cold" setting.

In accordance with the present invention. provision is made for indicating abnormal conditions of the apparatus by meansof the structure now to be described. At the upper end of lever l9, there is provided a double contact member 31 which is suitably insulated from the lever. Arranged cooperatively with the contact member 31 are contacts 38 and 39 which are carried respectively by arms 48 and 4|. The latter are in turn carried by supports 42 and 43, which are pivotally mounted on knife-edge pivots 44 and 45 mounted on the support I5.- Attached to arms 40 and 4| are a pair of inwardly-extending resilient arms 40a and Ma, the purpose of which will appear presently. A spring-toggle arrangement is associated with each of the arm supports 42 and 43 as shown. The said supports have V-shaped notches 46 and 41, respectively, to accommodate one end of the associated toggle spring 48 or 49. The opposite end of each spring is seated in a notched support 59 or 5i secured to the support or casing Hi. The arrangement is such that the contacts 38 and 39 are normally held in the positions shown against stops '52 and 53, the spring-toggle devices being slightly over center in the proper direction.

The purpose of the contacts 31-38-39 is to effect operation of an alarm or indicating device whenever the lever I9 moves in either direction beyond its normal range in response to an abnormal condition, as will be more fully described later. While the indicating device may take any suitable form, it preferably takes the form of a buzzer, as represented at 54. A conventional buzzer may be employed, as represented in Fig. 1, but it may be preferred to employ the improved buzzer illustrated in Figs. 4 and 5, which will be described hereinafter.

As illustrated, the indicating device may be energized by a battery 55 or it may be energized from the supply line 21 through a step-down transformer 56. In the apparatus shown, the alternative use of these sources of energy is made possible by means of a double-throw switch 51. Regardless of the source of energy utilized, the energizing circuit for the indicating device 54 will be closed whenever contact 31 engage eithe 01 setting, 1. e. during ordinary refrigerator operation, as previously pointed out. Therefore, in order to prevent operation of the indicator when the knob 22 is in the off and normal positions, there is provided a switch (see Fig. 3) comprising a cam 88 on shaft 24 and an associated contact finger 59 carried by the support or casing l5 but suitably insulated therefrom as by means of an insulating block 80. The cam 58 is formed so that the switch is open in the "off" and norma settings but is closed in the other settings. This switch is in series in the indicator circuit which includes conductor 6| connected to the contact finger 59 and conductor 62 connected to contact 31. Since cam 58 is grounded to the support or casing 19 through shaft 24, and since contacts 38 and 39 are also grounded to the casing through their pivotal supports, the circuit is completed through these grounded elements whenever contact 31 engages either of the contacts 38 and 39.

The pivoted arrangement of contacts 38 and 39 serves in conjunction with other elements now to be described to prevent operation of the indicating device at certain times when such operation would be undesirable. A plunger 83, slidably supported by bracket 63a and having an associated biasing spring 64, is adapted, when actuated downward, to engage arms 48a and Ma and thus move contact 38 or 39 away from contact 31. At the same time, the associated springtoggle device is moved over center. Projections 65 and 88 on lever l9 function to return the contact 38 or 39 to normal position, as described hereinafter.

Plunger 63 is actuated through a lever 61 pivoted at 68, which has a bifurcated portion 69 (see Fig. 3) disposed between a pair of spaced flanges 18 of the plunger. The lever 61 is moved clockwise about its pivot, as viewed in Fig. 1, to lower the plunger 63 whenever the control knob 22 is moved to the cold and continuous settings. This is accomplished by means of a cam 1| (see Fig. 3) on shaft 24, the said cam having projections 12 and 13 which actuate the lever 61.

- indicator is inoperative by reason of the fact that the contact arm 59 is out of engagement with the cam 58. This may be seen from Figs. 2 and 3 which show the o position of the elements. However, when the control knob is adjusted to decrease the operating temperature below normal," the cam 58 engages contact 59, thereby conditioning the circuit of the indicator for operation.

Assume that the apparatus has been operating at the normal setting and that it is desired to change to the cold setting. The operator turns the control knob counterclockwise (see Fig. 2) which has the effect of decreasing the tension of spring 2|, thereby causing lever ill to move clockwise about its pivot.

Due to the fact that the adjustment from normal" to "cold represents a substantial temventure decrease and such adjustment causes a substantial decrease in the pressure of spring 2 I,

the contact 31 would engage contract 29 and the alarm or indicator would be operated and would continue to operate until the temperature had been lowered to the cold setting, if it were not for the action effected by camlly Just before the "cold" setting is reached, the projection 13 actuates lever 61 to lower plunger 62 and to move contact 29 away from contact 31. Since the lever il is moving clockwise at this time, the projection 85 prevents contact 38 from moving away from its normal position. It should be noted that the resilience of arm 40a permits the lowering of plunger 83 even though the arm 40 is prevented from moving. Due to the spring-toggle 49, contact 89 is held out of its normal position so that the alarm or indicator is rendered inoperative. It should be noted also that the plunger 63 is permitted to rise by the time the control knob 22 reaches the "cold position, since the projection 12 is located ahead of the "cold" setting.

Since the motor-control switch 25 will have been closed by the movement of lever IS, the refrigerating system will operate to lower the temperature within compartment I to the value corresponding to the cold" setting. During this temperature lowering operation, the bellows I! will contract, causing lever Hi to move counterclockwise about its pivot 20 until it reaches its normal position at which the switch 25 is opened. Before the lever l9 reaches its normal position, however, its projection 66 will move arm 4| back to its normal position against stop 53, causing over-center action of the associated spring-toggle device. Thereafter, the refrigerating apparatus will operate at the "cold setting within the usual operating differential to either side of a predetermined mean temperature, and with the alarm or indicator arrangement conditioned for operation in the event of some abnormal condition causing the lever is to move excessively in either direction. A pair of stops I4 and are associated with lever I! and are arranged to permit just enough movement of the lever to effect firm engagement of the alarm contacts. Were it not for these stops, the lever I! might move sufllciently to cause undesired over-center action of the spring-toggle devices 48 and 49. In the event of an abnormal condition, the alarm circuit will be closed and will energize the alarm or indicator 54 as previously described.

If it should be decided to adjust the control setting to continuous," for example where it is desired to quick-freeze the stored foodstufis, the operator turns the control knob further to the continuous setting. This further decreases the tension of spring 2| and would cause undesired operation of the alarm or indicator if the latter were not rendered temporarily inoperative. In this instance, the cam projection 12 effects actuation of plunger 63 just before the control knob reaches the continuous setting, and the alarm circuit is rendered inoperative by the movement of contact 39 which is later restored to normal position, as above described.

Whenever the control knob 22 is moved in the reverse direction to raise the temperature, either from continuous to cold or from cold to "normal," the pressure of spring 2| is substantially increased causing substantial movement of lever l9 counterclockwise. In this instance also,

the alarm circuit would operate and would continue to operate throughout the temperatureraising operation if it were not rendered temporarily inoperative bythe means above described.

During such adjustment, however, one or the.

-' other of the cam projections I2 and 13 actuates the plunger 63 to move contact 38 away from contact 31, so as to prevent operation or the alarm or indicator. As the temperature rises to the desired value, lever I9 moves to its normal indication of any possible failure or abnormal condition which may occur. Lever 19 will be -moved excessively clockwise causing energization of the alarm by bringing contact 31 into engagement with contact 39, if any one of the following failures takes place: motor failure: failure of switch 25 to close; compressor failure; failure of a fuse in the motor circuit; loss of charge in the refrigerating system; complete power fail: ure and the like, any of these failures will cause the temperature in compartment H) to rise, thereby 'causing the bellows I"! to expand and thus move lever l9 clockwise until contact 31 engages contact 39.

Lever I9 will move counterclockwise and will bring contact 31 into engagement with contact 38 in response to loss ofthe charge in the bel lows H or failure of themotor switch 25 to open, or any condition resulting in excessively low temperature. In either instance, lever I! will be moved counterclockwise sufllciently to initiate operation of the alarm or indicator.

As previously mentioned,it may be desired to employ the indicating device shown in Figs. 4 and 5 in place of the conventional buzzer represented at 54 in Fig. 1. In the operation of the conventional buzzer, the contacts are normally closed and when the energizing circuit is completed. the actuating coil .or solenoid attracts the armature, thereby opening the circuit. Since the armature is spring-biased, usually by the resilience of its mounting, the contacts return to their normal closed position and the cycle is repeated.

The modified form of buzzer illustrated in Figs. 4 and 5 is so constructed as to effect a periodic or intermittent operation so as to reduce the energy consumption and to prolong the life of the device. The reduced energy consumption is particularly important where a battery isemployed as it greatly prolongs the life of the battery.

Referring to Figs. 4 and 5, the device comprises a support 16 on which the various parts are mounted, as illustrated. A pair of coils 11 and 18 are suitably mounted on a bracket 19 carried by the support 16.

Associated with the operating coils is an armature carried by a bimetal resilient strip 8!, one end of which is secured to a supporting terminal member 82. At its other end, the bimetal strip carries a contact 83 which normally engages a contact 84 carried by a supporting and terminal member 85.

The coil-supporting member 19 is formed of magnetic material and it serves to interconnect the magnetic core pieces of the respective coils. The armature 80 is also formed of magnetic material. 'Ihc coils are serially connected in the energizing circuit, which may include a battery 86 or other suitable source of energy. When the circuit is completed, the armature 80 is attracted by the energized electro-magnetic coils, thereby opening the contacts 83 and 84, which are again closed when the armature returns to its normal position. During the periods when current is flowing in the circuit, the bimetal strip 8| is heated by the current and finally accumulates sufliclent heat to cause it to flex in a direction to open the contacts. When this occurs, the device is rendered inoperative until the bimetal strip cools sufliciently to again permit closure of the contacts. Thus, the bimetal strip 8I eflects the desired intermittent operation of the buzzer.

The device also has provision for compensating for changes in the ambient temperature. To"

this end, the contact support 85 is also constructed as a bimetal member which counteracts any effects of ambient temperature changes on the main bimetal member 8|. For example, any rise in ambient temperature tending to flex the bimetal strip 8| downward will cause the bimetal member 85 to move correspondingly, thereby maintaining a constant contact pressure between the contacts 83 and 84. Member 85, however, should be formed of low resistance material and should have a relatively great cross-sectional area so as to minimize the heating effect of current flowing through it. Otherwise this member would tend to counteract the function of the bimetal strip 8|.

In Fig. 6 there is shown a modification of the apparatus of Fig. 1. In this instance, the cam II (see Fig. 1) and the associated lever 61 are dispensed with and the plunger 63b is constructed and arranged as a push-button for manual operation by the user. Thus, instead of the alarm system being rendered inoperative automatically in response to certain adjustments of the control knob 22, as previously described, it is necessary for the operator to depress the push-button 63b whenever the adjustment of the control knob is such as to efi'ect undesirable operation of the alarm or indicator. That is to say, each time the operator adjusts the control knob to the cold or continuous setting, the plunger 83b must be depressed to prevent or interrupt the consequent undesired operation of the alarm or indicator. Achievement of the desired temperature will, of course, automatically recondition the alarm for operation by the action of projections 65 and 96 as above set forth.

In Fig. '7, there is illustrated another embodiment of the invention in which the alarm device serves additionally as a signalling device to indicate the attainment of certain desired temperatures, and in which the alarm system is separated from the thermostatic control device. The refrigerating apparatus is again shown on a greatly reduced scale, and the food storage compartment is shown in dotted outline at I011. The refrigerating system is controlled by an adjustable thermostatic control device I4a, which is similar to the device I4 of Fig. 1, except that the alarm-actuating elements are eliminated. The elements of the device I4a are numbered in correspondence to those of the device I4 of Fig. 1, empoying the suflix n. in each instance. It is believed unnecessary to describe the structure and operation of device I4a, as these will be clear from the foregoing description. In this instance, as before, the refrigerating apparatus is operated at the desired temperature level by adjusting the control knob 22a.

The mechanism for controlling the alarm or indicator 54a comprises a separate unit or .device 81 which is actuated through a separate feeler bulb (not visible) and a conduit 88 leading to a bellows 89. The latter engages a lever 90,

pivoted at 81, and operates against a spring 92,

whose pressure is adjustable by means of the screw 98. At its upper end, lever carries a double contact member 94 which is insulated from lever 90. A pair of contacts 95 and 98 are arranged cooperatively with contact member 90 to complete the alarm circuit whenever lever 90 moves excessively in either direction. The structure of the device 81 as thus far described will be clearly understood from the preceding description as it will be recognized that this device is generally similar to that employed in the embodiment of Fig. 1.

Contacts 95 and 96 are carried by a bracket 91 which is suspended from a laterally movable support 98 having an adjusting knob 99. To permit lateral movement of the knob and the associated contact support, the casing I00 is slotted at IN. The contact support 98 also carries a resilient detent member I02 whose ends are adapted to seat in recesses I03, I04 and I05, as described hereinafter.

Associated with lever 90 is a lever arm I08 which is pivoted on the same pivot 9I, and which has a projection I0'I adapted to engage a flange I08 on lever 90 under certain conditions, as described hereinafter. The free end of lever I08 extends through a slot I09 in the casing wall and is normally urged against the lower edge of the slot by a spring IIO, one end of which is secured to lever I06 at I I I, while the other end of the spring is anchored at H2 to a bracket II3 carried by screw II4. It will b seen that rotation of screw I I4 varies the position of bracket I I3 and thereby varies the pressure of spring H0. The purpose of this arrangement will be described presently.

Considering the operation of the apparatus of Fig. 7, if the knob 22a is adjusted to the normal" setting, the alarm or indicator is rendered inoperative by the switch 58a--59a, as previously described. It will be noted that the circuit for the alarm or indicator device extends through the casing I5a and the shaft 24a, upon which the cam 58a is mounted.

The adjusting spring 92 of the alarm control mechanism 81 is preferably under pressure so that the parts are positioned substantially as shown when the temperature within compartment No is at a value corresponding to the "cold" setting of knob 22a. With such setting of the knob 22a, the alarm device is rendered operative by the closure of switch 58a59a, as previously described.

Assume that the apparatus has been operating at the "normal temperature setting. Under such conditions, the bellows 89 will be expanded to such an extent as to cause engagement of contact 94 with contact 96, but the alarm is inoperative due to the open condition of switch 58a59a. Assume now that the operator adjusts knob 22a to the cold position, thereby closing switch 58a59a. The alarm or indicator will be energized as a result of such adjustment, and the operator then moves knob 99 to the right until the. right-hand end of detent I02 engages'recess I05.

Such adjustment of knob 99 will disengage the contacts 94 and 96, thereby opening the indicator circuit.

As the temperature within compartment, I0a is lowered, the bellows 89 contracts, causing counterclockwise movement of lever 90. When the "cold temperature is reached, contact 94 will engage contact 95, thereby energizing the alarm or indicator which apprises the operator of the fact that the temperature has reached the "cold" value, Thereupon the operator moves knob 09 back to the position shown, withthe left-hand end of detent I02 seated in recess I04. The apparatus is then conditioned for operation at the cold temperature. Should the temperature rise above a safe value for maintaining frozen foods, the bellows 89 will expand sufilciently to cause engagement of contacts 94 and 96 so as to energize the alarm or indicator.

Assume now that the operator adjusts the control knob 22a to the continuous setting. As the temperature within compartment Ia is lowered further, the bellows 89 contracts, causing lever 90 to move counterclockwise, thus moving contact 04 toward contact 95. Engagement of these contacts is prevented, however, by the lever I06 and its associated spring IIO. As the lever 90 moves counterclockwise, its flange I00 engages the projection I0'I on lever I06 and consequently, the lever 90 encounters the resistance of spring 0 which is such as to prevent sufficient movement of lever 90 to effect engagement of the contacts 04 and 95.

In the event, however, that the bellows 09 loses its charge and its internal pressure decreases substantially to zero, the force of spring IIO will be overcome by that of spring 02, causing lever 90 to move counterclockwise sufliciently to effect engagement of contacts 90 and 85. Thus, the operator will be apprised that an abnormal condition exists. alarm circuit by moving knob 99 to the left until the left-hand end of detent I02 engages recess I03.

Thus, it will be seen that the apparatus of Fig. '7 provides the desired protection against spoilage of foodstufis which may be stored in large quantity in a frozen condition. Moreover, this form of the apparatus has the advantage that it indicates when the desired temperature is reached after adjustment of the temperature control knob from the ordinary refrigerating level to a freezing level of much lower temperature.

Although certain embodiments of the invention have been illustrated and described, it will be apparent that other embodiments and modifications may be resorted to without departing from the scope of th invention. For example, the number of temperature settings may be varied at will and the alarm control mechanism may be modified accordingly. Other possible variations will be readily apparent to those skilled in the art.

I claim:

1. A controlling and indicating apparatus for a refrigerator, comprising thermal responsive means arranged for actuation according to the temperature within a compartment of said refrigerator, switch means operable by said firstnamed means and adapted to control the operation of said refrigerator, electrical indicating means, and additional switch means operable by said first-named means in response to predetermined excessively high and low temperatures within said compartment, said last-named switch means being arranged to control said indicating means so as to give an indication of excessively high or low temperature.

2. A controlling and indicating apparatus for a refrigerator, comprising thermal-responsive means arranged for actuation according to the temperature within a compartment of said refrigerator, a member movable by said means in opposite directions in response to temperature variations, switch means operable by said mem- The operator may interrupt the 10 ber and adapted to control the operation of said refrigerator, electrical indicating means, and ad ditional switch means operable by said member in response to predetermined excessivelyhigh and low temperatures within said compartment, said last-named switch means being arranged to control said indicating means so as to give an indication of excessively high or low temperature.

3. A controlling and indicating apparatus for a refrigerator, comprising thermal-responsive means arranged for actuation according to the temperature within a compartment of said refrigerator, a lever movable by said means in opposite directions in response to temperature variations about an optimum temperature, switch means operable by said lever and adapted to control the operation of said refrigerator, contact means carried by said lever, other contact means arranged cooperatively with said first contact means and engageable thereby whenever said lever moves excessively in response to excessively high or low temperature within said compartment, and electrical indicating means arranged to be actuated by the engagement of said contact means so as to give an indication of excessively high or low temperature.

4. In an apparatus for controlling a refrigerator and for indicating failure or abnormal operation thereof due to various causes, a thermostatic device arranged for actuation according to temperature variations within a compartment of said refrigerator, means movable by said devicein accordance with temperature variations above and below a predetermined desired temperature, switch means operable by said first-named means and adapted to control the operation of said refrigerator, additional switch means operable by said first named means whenever the latter moves excessively in either direction, and electrical indicating means arranged to be actuated by said last-named switching means so as to indicate an abnormal condition.

5. In an apparatus for controlling a refrigerator and for indicating failure or abnormal operation thereof due to various causes, a thermostatic device of the fluid-pressure type arranged for actuation according to temperature variations within a. compartment of said refrigerator, a lever movable by said device in accordance with temperature variations above and below a predetermined desired temperature, switch means operable by said lever and adapted to control the operation of said refrigerator, contact means carried by said lever, other contact means arranged cooperatively with said first contact means and engageable thereby whenever said lever moves excessively in either direction, and electrical indicating means arranged to be actuated by the engagement of said contact means so as to indicate an abnormal condition.

6. In combination with refrigerator apparatus, means for indicating an abnormal condition of said apparatus, and means for rendering said indicating means temporarily inoperative and for automatically restoring the operativeness of said indicating means.

7. In a refrigerator system, adjustable thermostatic means adapted to control the operation of the refrigerator, means for indicating an abnormal condition of the refrigerator system, and means responsive to certain adjustments of said thermostatic means for rendering said indicating means temporarily inoperative.

8. In a refrigerator system, adjustable thermostatic means adapted to control the operation of the refrigerator, means for indicating an abnormal condition of the refrigerator system. means responsive to certain adjustments of said thermostatic means for rendering said indicating means temporarily inoperative, and means for automatically restoring said indicating means to its operative condition.

9. In a refrigerator system. adjustable thermostatic means adapted to control the operation of the refrigerator, a movable member actuated by said thermostatic means, switch means operable by said member in response to abnormal positioning thereof, electrical indicating means actuated by said switch means, means responsive to certain adjustments of said thermostatic means for rendering said switch means inoperative, and means on said movable member for restoring the operative condition of said switch means.

10. In an apparatus for indicating excessively high or low temperature within a refrigerated area, thermal-responsive means arranged for actuation according to the temperature within said area, a member movable by said means in opposite directions in response to temperature variations about an optimum temperature, first contact means movable by said member, second contact means arranged cooperatively with said first contact means and enga'geable therewith whenever the temperature within said area is excessively high or low, electrical indicating means arranged to be actuated by the engagement of said contact means so as to give-an indication of excessively high or low temperature, and means for eifecting relative movement between said first and second contact means so as to prevent engagement there-between.

11. In an apparatus for indicating excessively high or low temperature within a refrigerated area, thermal-responsive means arranged for actuation according to the temperature within said area, a member movable by said means in opposite directions in response to temperature variations about an optimum temperature, contact means carried by said member, other contact means arranged cooperatively with said first contact means and engageable thereby whenever the temperature within said area is excessively high or low, electrical indicating means arranged to be actuated by the engagement of said contact means so as to give an indication of excessively high or low temperature, and manuallyoperable means for moving said other contact means so as to prevent engagement thereof by said first contact means.

12. In an electrical-refrigerator system a thermostatic control device including a pressureresponsive means and an opposing spring, means for adjusting said spring to thus control the operation of said system, a movable member arranged to be positioned by said thermostatic device, contact means on said member, other contact means arranged cooperatively with said first contact means and engageable thereby when said member is abnormally positioned, electrical indicating means arranged to be actuated by the engagement of said contact means, means responsive to certain adjustments of said springadjusting means for moving said other contact thermostatic control device including a pressureresponsive means and an opposing spring, means for adjusting said spring to thus control the operation of said system, a lever arranged to be positioned by said thermostatic device, contact means on said lever, a pair of spaced contacts arranged cooperatively with said contact means and engageablethereby when said lever is abnormally positioned, electrical indicating means arranged to be actuated by the engagement of said contact means with either of said contacts. means responsive to certain adjustments of said spring-adjusting means for moving said contacts so as to prevent engagement thereof by said contact means, and a pair of arms on said lever for restoring said contacts to normal position when said lever is normally positioned.

14. In an electrical refrigerator system, adjustable thermostatic control means having a plurality of operating settings and adapted to control the operation of the refrigerator, electrically-operable signal means, an energizing circuit for said signal means, and a switch in said circuit operable in response to adjustment of said control means and adapted to open said circuit when said control means is adjusted to one of itsoperating settings.

15. In refrigerator apparatus, means for indicating abnormal temperature conditions thereof, adjustable means for effecting a change in the operating temperature of said apparatus from one value to another, and means for rendering said indicating means temporarily ineffective un til the completion of said change and the attainment of the desired operating temperature.

16. In a refrigerator adapted to maintain foodstuffs in a frozen condition, means including a manual control member for initiating and controlling the operation thereof, said member being adjustable to a certain position to effect operation at sub-freezing temperature, electrically-operable signal means for indicating a substantial temperature rise above the sub-freezing temperature, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, and means for rendering said switch inoperative when the refrigerator temperature is substantially above the subfreezing temperature due to a normal operating condition.

1'1. In a refrigerator adapted to maintain foodstuffs in a frozen condition, means including a manual control member for initiating and controlling the operation thereof, said member being adjustable to a certain position to effect operation at sub-freezing temperature, electricallyoperable signal means-for indicating a substantial temperature rise above the sub-freezing temperature, a thermostatically-contro1led switch in circuit with said signal means to control the operation thereof, means for rendering said switch inoperative when the refrigerator temperature is substantially above the sub-freezing temperature due to a normal operating condition, and means for automatically rendering said switch operative when the refrigerator temperature decreases to the sub-freezing temperature.

18. In a refrigerator adapted to maintain foodstuffs in a frozen condition, means including a manual control member for initiating and controlling the operationthereof, said member being adjustable to a certain position to effect operation at sub-freezing temperature, electricallyoperable signal means for indicating a substantial temperature rise above the sub-freezing temperature, a thermoStatioally-controlled switch in circuit with said signal means to control the operation thereof, means controlled by said member for rendering said switch inoperative when the refrigerator temperature is substantially above the sub-freezing temperature due to a normal operating condition, and means for antomatically rendering said switch operative when the refrigerator temperature decreases to the sub-freezing temperature.

19. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures including above-freezing and sub-freezing temperatures, electrically-operable signal means for indicating a substantial temperature rise when the control means is set for operation at sub-freezing temperature, thermostatically-controlled switch means for actuating said signal means in response to such temperature rise, and means controlled by said control means for preventing actuation of said signal means when the control means is set for operation at above-freezing temperature.

20. In a refrigerator, 9. refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from a temperature corresponding to a setting of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, and means for rendering said switch inoperative when the refrigerator temperature is at a value substantially different from the last-mentioned temperature due to a different previous setting of said control means or due to the fact that the refrigerator has just been placed in operation.

21. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from a temperature corresponding to a setting of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, means for rendering said switch inoperative when the refrigerator temperature is at a value substantially different from the lastmentioned temperature due to a different'previous setting of said control means or due to the fact that the refrigerator has just been placed in operation, and means for automatically readjusting said switch to its operative condition when the said temperature has been reached.

22. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at diflerent temperatures, electrically-operable signal means for indicating substantial variation from temperatures corresponding to different settings of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, means operable by said control means for adjusting said switch according to the setting of the control means, such adjustment of the switch tending to actuate it and thus tending to cause undesired operation of said signal means, and means for rendering said switch inoperative until the refrigerator reaches the temperature corresponding to the setting of said control means.

23. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operablesignal means for indicating substantial variation from temperatures corresponding to different settings of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, means operable by said control means for adjusting said switch according to the setting of the control means, such adjustment of the switch tending to actuate it and thus tending to cause undesired operation of said signal means, means operable by said control means for rendering said switch inoperative at the same time it is adjusted, and means for automatically restoring the operative condition of said switch when the refrigerator reaches the temperature corresponding to the setting of said control means.

24. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from'temperatures corresponding to different settings of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, said switch comprising a movable contact member adjustable by said control means and a pair of other contact members movable to operative and inoperative positions, the adjustment of said first member tending to actuate the switch and thus tending to cause undesired operation of said signal means, and means for moving said other contact members to their inoperative positions until the refrigerator reaches thetemperature corresponding to the setting of said control means.

25. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from temperatures corresponding to different settings of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, said switch comprising a movable contact member adjustable by said control means and a pair of other contact members movable to operative and inoperative positions, the adjustment of said first member tending to actuate the switch and thus tending to cause undesired operation of said signal means, means for moving said other contact members to their inoperative positions when said first member is adjusted by the control means, and means on said first member for restoring said other members to their operative positions when the refrigerator reaches the temperature corresponding to the setting of said control means.

26. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from temperatures corresponding to different settings of said control means, a thermcstatically-controlled switch in circuit with said signal means to control the operation thereof, said switch comprising a movable contact member adjustable by said control means and a pair of other contact members movable to operative and inoperative positions, the adjustment of said first member tending to actuate the switch and thus tending to cause undesired operation of said signal means, means operable by said control means for moving said other contact members to their inoperative positions when said first member is adjusted by the control means, and means on said first member for restoring said other members to their operative positions when the refrigerator reaches the temperature corresponding to the setting of said control means.

27. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for indicating substantial variation from a temperature corresponding to a predetermined setting of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, said switch comprising a thermostatically movable contact member and a normally-stationary dual-contact member, and manual means for moving said last-named contact member to prevent operation of said switch when the refrigerator temperature is at a value substantiall different from the last-mentioned temperature due to a different previous setting of said control means or due to the fact that the refrigerator has just been placed in operation.

28. In a refrigerator, a refrigerating system for maintaining a desired temperature, adjustable control means having a plurality of operating settings to effect operation at different temperatures, electrically-operable signal means for. indicating substantial variation from a temperature corresponding to a predetermined setting of said control means, a thermostatically-controlled switch in circuit with said signal means to control the operation thereof, said switch comprising a thermostatically movable contact member and a normally-stationary dual-contact member, manual means for moving said last-named contact member to prevent operation of said switch when the refrigerator temperature is at a value substantially higher than the last-mentioned temperature due to a previous higher setting of said control means or due to the fact that the refrigerator has just been placed in operation, and means for preventing operation of said switch when said control means is adjusted to a setting lower than said predetermined setting.

29. In a refrigerator adapted to maintain subfreezing temperature, electrically-operable signal means, thermostatic means including a bellows responsive to the refrigerator temperature, and dual-action switch means operable by said bellows and adapted to actuate said signal means in the event of substantial temperature rise causing expansion of the bellows or in the event of substantial contraction of the bellows.

JOHN J. BAUMAN.

REFERENCES CITED The following references are of record in the file of this patent:

. UNITED STATES PATENTS Samuels July 16, 1940 Disclaimer 2,447,893.-J0hn J. Bauman, Abington, Pa. ALARM SYSTEM FOR ELECTRIC RE- FRIGERATORS. Patent dated Aug. 24, 1948. Disclaimer filed Sept. 21, 1949, by the assignee, Philco Corporation.

Hereby enters this disclaimer to claims 6 and 15 of said Letters Patent.

[Ofiicz'al Gazette October 25, 1949.]

Disclaimer by the assignee, Phzlco Corporation.

Hereby enters this disclaimer to claims 6 and 15 of said Letters Patent. [Oflicial Gazette October 25, 1949.]

ALARM SYSTEM FOR ELECTRIC RE- 948. Disclaimer filed Sept. 21, 1949, 

